Such an in-wheel suspension is described, for example, in Japanese Patent Application Publication No. JP-A-10-338009. The in-wheel suspension described in this publication includes a hub that supports a wheel. The wheel mainly includes a disc and a rim. The rim has a reference width and a reference diameter. The in-wheel suspension includes a wheel carrier that defines the rotational axis of the hub, and a guide member that guides the movement of the wheel carrier with respect to a support member in the axial direction. The support member includes fitting means for fitting the support member to a chassis of a vehicle. The wheel carrier is fitted to the guide member by a long-and-thin single bar, and slides according to the guidance by the guide member. The wheel carrier is prevented from rotating on the sliding axis. The wheel carrier is fitted to the both ends of the bar. The in-wheel suspension includes means for supporting a load of the vehicle transmitted to the wheel carrier by the support member. The wheel carrier, the bar, and the guide member are housed in the wheel along the diameter defined by the reference diameter. The wheel carrier, the bar, and the guide member are housed in a limited space having a shape of a cylinder where one of the surfaces of the cylinder, which extend in the axial direction of the wheel carrier, bar, and the guide member, is defined by the disc of the wheel and the other surface is defined by a virtual surface contacting the rim.
To ensure the stability of the vehicle, changing a toe-angle of a tire/wheel assembly when the tire/wheel assembly jounces/rebounds is effective. In the above-described structure, a steering mechanism is provided, and the tire/wheel assembly can be steered. However, the tire/wheel assembly can actually move only along the sliding shaft when the tire/wheel assembly jounces/rebounds. Unless the steering operation is performed using the steering mechanism (namely, unless a driver operates a steering wheel, or unless an actuator is actuated in the case where active rear steer (ARS) is employed), the toe-angle of the tire/wheel assembly does not change when the tire/wheel assembly jounces/rebounds.
Even in such a structure, a support member can be fitted the vehicle body by a link such that the toe-angle of the tire/wheel assembly changes when the tire/wheel assembly jounces/rebounds. In such a case, however, a relatively long link needs to be provided in order to obtain required characteristics of a change in the toe-angle. This prevents size reduction of a suspension and an increase in a space in a vehicle compartment, resulting in reduction of the advantages of an in-wheel suspension.